DE 102006015 051 describes a laser device for the treatment of the eye. Sensitive regions of the eye are irradiated in this process.
The applied laser radiation can pose a risk to the retina and especially to the macula. Pertinent standards, for instance, IEC 60825-1, provide reliable threshold values for the irradiation of the retina. The maximum permissible exposure values (MPE values) are threshold values pertaining to a safe radiation strength (watts per square centimeter) or radiation (joules per square centimeter). These values are stipulated separately for the skin and eyes. Such values are reference values that have been ascertained experimentally. Irradiation of the retina, especially of the macula—the site of the sharpest vision or of the optic nerve head—should be kept to a minimum since these are particularly sensitive places of the fundus of the eye. Laser radiation in the visible and near-infrared spectra (wavelength of about 400 nm to 1400 nm) penetrates virtually without diminishing all the way to the retina and can damage the very sensitive macula or else the pupil or the optic nerve head. When laser radiation is employed, the maximum permissible exposure values are always complied with everywhere on the fundus of the eye. If an anterior segment of an eye is exposed to a laser beam, radiation usually reaches the fundus of the eye as well. Even if an optical breakdown is achieved in the focus of the laser radiation for purposes of processing the tissue located there, laser radiation that was not absorbed still reaches the fundus of the eye and thus also particularly sensitive regions of the retina.